Writers 
So it is often the case that what we give life will return to us. A farmer will not be able to plant weeds and end up with corn. We can't consistently sow bad things in our lives and reap good things. Thoughts, words, actions, relationships, habits and choices are all inputs and over time they can affect the kind of output we are having.
One of the most powerful inputs is your thoughts. Living in a state of fear, negativity, doubt and discouragement can impact your confidence and decisions. Conversely, if you can cultivate positive thoughts, wisdom, hope, determination, etc., in your mind, then you are better equipped to handle problems. This is not simply about leaving issues unaddressed; it's about finding a healthy and constructive way to deal with issues.
Information you take in is important too. The world will be shaped by what you read, watch, hear and learn. The more useful skills you learn and more knowledge you acquire, the better you will be able to make decisions. However, if you are continually putting yourself in situations that tempt you to be lazy, hateful, dishonest, or unhealthy, you can become that way!
Another form of input is your habits. Success doesn't come as a single great thing. It can be caused by small things done over and over. Academic improvement can be achieved by studying regularly. Competence can be achieved through practice. Productivity can be achieved with effective time management. Similarly, procrastination, carelessness, and lack of discipline can lead to less than stellar results over time.
People around you can also affect your output. A good friend can help you to develop, to learn, to be responsible. Support during challenging times can come from positive relationships. That's why it's crucial to make a conscious choice about the type of influence that you're letting in. Do not turn away anyone who is different from you, but be aware when they are constantly pulling you away from your values and goals.
Your words are other important inputs. Your self-talk and the words you use with others can affect your attitude and actions. Positive affirmations can establish confidence and positive negativity can establish discouragement. So, learn to speak wisely, kindly and purposefully.
First and foremost, spiritual input is important. Prayer, Scripture, worship and fellowship can give guidance, strength and hope to those who believe in God. What you repeatedly allow to develop your heart can impact how you'll react to life.
If you aren't pleased with the outcomes you're not just grumbling about the output. Examine the input. Question yourself - what do I feed my mind? What do I do that is not part of my habits? Who influences me? What am I learning? What choices do I have to make each day?
While you can't control everything that's going on around you, you can choose to let better things into your life. Adjust the input, tweak the process and patiently and consistently, you'll start to notice an improvement in the output.
Keep in mind: Once you put it into your life, it will impact the future of it.